The analyzing power in proton-proton scattering has been measured at bombarding energies of 5.05 and 9.85 MeV to an accuracy of ±5×${10}^{-5\mathrm{}}$. The measurements were combined with existing cross-section data to obtain model-independent $S$- and $P$-wave phase shifts at these energies. In addition, the first experimental determination of the $P$-wave scattering lengths and effective ranges is reported. These are compared to model values and their use in obtaining improved $S$-wave parameters is suggested.

Adiabatic time-dependent Hartree-Fock theory is used to describe the motion of the system around stable equilibrium. It is shown that after a proper quantization of the collective variables this method leads to matrix elements of operators between collective states which are identical to those obtained in the generator coordinate method. In particular both predict equal zero-point motion effects in the ground-state density and energy.

The measured intensity and polarization of Balmer-alpha radiation resulting from 40-80-keV collisions of ${\mathrm{H}}^{+}$ on He exhibited a strong dependence on electric fields applied axially along the beam direction. With use of a density matrix formalism the collisionally produced electric dipole moment for the $n=3\mathrm{}$ state was found to be large, reaching $4.4e{a}_0$ at the lowest collision energy. The center of the electron cloud distribution was found to lag behind the proton.

Described here is a collective accelerator based on magnetically confined plasma rings. Typical rings which have been produced and which have 10-kJ magnetic energy and 0.1 to 10 C of nuclei are predicted to be accelerated magnetically to 10 MJ or higher in acceleration lengths of 100 m. Applications are discussed of current drive in tokamak fusion reactors, fueling and heating magnetic fusion reactors, transuranic element synthesis, and, for focused rings, a high-energy density driver for inertial confinement fusion.

A quantitative theory of melting in two dimensions via the spontaneous generation of grain boundaries is presented. It is found that as the temperature is increased, grain boundaries are generated before the dislocations unbind. Also discussed are (a) the nature of the transition, (b) the coupling of the grain boundaries to a density change, (c) the existence of a hexatic phase, and (d) comparisions with recent computer simulations.

It is shown that the competition between short-range repulsion and the interaction between quadrupole moment and fluctuating field gradient strongly influences the elastic softening and ferroelastic instabilities of ionic molecular solids. This theory is applied to explain the ferroelastic properties of alkali cyanides and superoxides.

The first measurements are reported of the Rayleigh linewidth of binary liquid films near the critical point for which the correlation length is comparable to the film thickness. The present data are in good agreement with the predictions of renormalization-group theory for binary liquids in three spatial dimensions with no adjustable fitting parameters. No influence of finite size or bounding surfaces on the linewidth is observed.

In hexyloxycyanobiphenyl-octyloxycyanobiphenyl (60CB-80CB) binary mixtures displaying reentrant behavior, the smectic elastic constant, $B$, deviates from a simple power law of the form $B=B_1{(T_{\mathrm{NA}}-T)}^{\varphi }$ and levels off as $T\to T_{\mathrm{NA}}$. This behavior is consistent with the Nelson-Toner dislocation-unbinding model of the transition.

The solitons of spin-density-wave and charge-density-wave systems of arbitrary commensurability are discussed. Spin-density-wave systems can have both "scalar" (i.e., phase and amplitude) solitons as well as "polarization" solitons. A simple picture is presented to account for the various charge and spin states of the scalar solitons of both systems. Localized states are also found in polarization solitons. Unlike those of the scalar solitons, they are in general nondegenerate.

Neutron-diffraction and bulk resistivity measurements on single crystals of Er${\mathrm{Rh}}_4$${\mathrm{B}}_4$ have revealed an intermediate phase below 1.2 K, where both a ferromagnetic structure and a transverse linearly polarized modulated structure, with a wavelength of ∼ 100 Å, are observed. The modulated moment disappears suddenly below 0.71 K, with loss of superconductivity and a transition to a normal ferromagnetic state. The intermediate phase is interpreted as being one of coexisting ferromagnetic domains and superconducting domains.

Orthopositronium annihilation rates have been measured in ethane gas for densities in the range 1.8 to 286 amagats at 306.4 K. The behavior of the measured annihilation rates at densities up to about 70 amagats can be explained in terms of a simple density fluctuation model. New features are observed at higher densities of ethane at 306.4 K.

Theoretical calculations are presented which show that the enhancement predicted by the particle plasmon model of surface-enhanced Raman scattering is limited by radiation damping. The damping becomes more severe as particle size increases, while the enhancement produced by small particles is limited by surface scattering. Good agreement between theory and experimental measurements of the wavelength dependence of surface-enhanced Raman scattering on lithographically produced microstructures is found when radiation damping is taken into account.

It is shown that a general class of transverse electromagnetic waves with $\overrightarrow{\mathrm{E}}\parallel \overrightarrow{\mathrm{B}}$ exists. These waves possess magnetic helicity. In the case of plasma, both a high-frequency branch with ${\omega }^2={{\omega }_p}^2+k^2{c}^2$ and a low-frequency branch with $\omega \approx 0$ are allowed. The zero-frequency branch corresponds to the force-free magnetic field $\nabla \times \overrightarrow{\mathrm{B}}=k\overrightarrow{\mathrm{B}}$. These waves also exist in magnetized plasmas over a wide frequency range.

The eigenvalues, $E_{\mathrm{nl}}$, of the radial Schrödinger equation are approximated by $c_k(E=E_{\mathrm{nl}})=0\mathrm{}$ ($k=2, 3, \dots \infty$), where $E$ is the energy and the $c_k$ are the power-series coefficients of $f\left(\mathcal{r}\right)=\frac{\psi \left(\mathcal{r}\right)}{\left[{\mathcal{r}}^{l+1\mathrm{}}w\right(\mathcal{r}\left)\right]}$ with $\psi \left(\mathcal{r}\right)$ the wave function and $w\left(\mathcal{r}\right)$ a weight function. This is an extension of the method used to solve certain potentials exactly where $c_k(E=E_{\mathrm{nl}})=0\mathrm{}$ terminates a power series.

It is shown that the ratio of forward to backward scattering cross sections plays the same role for neutrino-electron scattering as does the original $\rho$ parameter for muon decay. Values of the ratio greater than 2 imply that the neutrino is a Dirac particle and that the tensor interaction is present in the effective Hamiltonian; values less than 2 do not exclude the Majorana case.

In an experiment measuring charmed-particle lifetimes with a hybrid emulsion spectrometer, 1248 neutrino and antineutrino interactions produced by the wide-band beam at Fermi National Accelerator Laboratory have been located. Twenty-one candidates for the decay of neutral charmed particles are found. The lifetime for the $D^0$ based on the sixteen constrained events of this sample is measured to be ${2.3}_{-0.5\mathrm{}}^{+0.8\mathrm{}}$×${10}^{-13\mathrm{}}$ sec.

The $K_L-K_S$ mass difference provides a stringent constraint on the mass ($M_R$) of the charged right-handed gauge field occurring in a "manifest" left-right-symmetric electroweak theory, yielding $M_R\gtrsim 1.6$ TeV. Taken in the context of a grand-unifying gauge theory, e.g., O(10), such a large bound on $M_R$, along with the measured value of ${{sin}^2\theta }_W$, implies that $M_R\gtrsim {10}^9$ GeV.

Cross sections for the production of heavy actinides in damped collisions of ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ ions with ${}_{}{}^{248}{}_{}{}^{}\mathrm{Cm}$ targets are reported and compared with similar data for other projectiles. The relatively small differences in the formation rates of a given isotope made by different projectiles indicate a balance between increased mass transfer probability with increasing projectile mass and a concurrent decrease in survivability because of an increase in excitation energy.

Cosmic-ray nuclei have been observed to produce 2072 secondary fragments in nuclear interactions detected in nuclear emulsions. These fragments produce 557 further interactions. Previous reports that these secondary nuclei show anomalously short mean free paths near their point of origin are confirmed. This effect can be interpreted as being due to all fragments having cross sections about twice normal for some ${10}^{-10\mathrm{}}$ sec after creation, or to a small fraction having cross sections an order of magnitude greater than normal.

The ($n, p$) reactions to the analog giant magnetic dipole states, the inverse of the transitions in allowed Gamow-Teller $\beta$ decay, have been measured for ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, and ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ for forward angles using 59.6-MeV neutrons. With use of a relation between $\sigma \left(0\mathrm{}°\right)$ and the $\beta$-decay matrix elements, there results ${v_{\sigma \tau }}^c\mathrm{}\left(0\right)=157\mathrm{}\pm 11$ MeV ${\mathrm{fm}}^3$ for the $l=0\mathrm{}$, isovector part of the effective spin-flip nucleon-nucleon interaction. Comparison with 120-MeV ($p, n$) reactions indicates that ${v_{\sigma \tau }}^c$ has a small energy dependence in the range 60 to 120 MeV.